Scientists at the CSIR-Institute of Genomics and Integrative Biology (IGIB), New Delhi, have successfully developed an inexpensive paper-based test for COVID-19 that returns fast results similar to a pregnancy test.
Name Feluda, the testing kit is based on a gene-editing technology called CRISPR. It returns Coronavirus test results in less than an hour and costs less than $7.
Central Drugs Standard Control Organization (CDSCO), India’s apex drug regulatory authority, has also approved Feluda for commercial use. Whereas, Tata Group, the Indian multinational conglomerate, is all set to mass-produce Feluda.
If everything goes according to plan, the kit developed by Indian scientists could become the world’s first widely available paper-based Coronavirus test.
Prof. Krishnaswamy Vijay Raghavan, Principal Scientific Adviser to the Indian government, has said:
Feluda is a simple, precise, reliable, scalable, and frugal test.
With more than 6.7 million confirmed Coronavirus cases and over 103,600 deaths, India is the world’s second most affected country by the deadly infection. The US remains the country most affected by the Coronavirus pandemic with over 7.7 million confirmed cases and more than 215,000 deaths.
How Feluda works?
As discussed above, Feluda is based on a gene-editing technology known as CRISPR.
Gene-editing technology is primarily used to prevent infections and treat afflictions like sickle cell disease. Gene-editing works in the same as a word processor- it is like correcting a word by removing the incorrect letter and inserting the correct one. CRISPR can remove and add a single genome letter, such is the precision of this gene-editing technology.
CRISPR technique used in Feluda latches on to set of letters of a gene carrying the signature of the SARS-COV-2, the Coronavirus which causes the COVID-19 infection, highlights it and provides the result on a paper.
Two blue lines mean that a sample has returned a positive Coronavirus result while a single blue line indicates a negative result.
Before sending Feluda to CDSCO for approval, Indian scientists tried the kit on more than 2,000 samples. Samples for Feluda were gathered in the same way as a PCR test; a nasal swab inserted into the nasal passage through the nose to collect the sample.
Feluda returned test results with a 96% sensitivity and 98% specificity. The accuracy of the kit depends on these two indicators.
A sensitive test detects almost everyone who has the Coronavirus and has a low false-negative rate while the specific test rules out almost everyone who doesn’t have the virus and has a low false-positive rate.
Currently, India is using two types of Coronavirus testing techniques; PCR swab test and rapid antigen test. A PCR test is expensive but more reliable due to low false positive and false negative test rates. On the other hand, the rapid antigen test is inexpensive but unreliable due to a high false-negative rate.
Dr. Anurag Agarwal, Director of CSIR-IGIB, is hopeful that Feluda, once it hits the markets, will replace the PCR swab test because it is inexpensive and more accurate.
Feluda has the reliability of the PCR test. It is quicker and can be done in smaller laboratories which don’t have sophisticated machines to perform PCR tests.